Probably what would be most useful would be documentation on creating specific segments like wyes, the use of curved turnouts to save space and connecting various lines of 3-rail track.
Atlas has much of this information in the Atlas All Scales Track Catalogue. See page 118 for connecting Atlas track to existing track. Pages 110-112 for various wyes and turnout combinations. This is not the straight to straight, curve to curve stuff.
Lionel also has several pages of similar information in its 2014-2015 Track and Power Catalogue.